The purpose of the study is twofold: 1) to identify specific behavioral changes in offspring of women who used phencyclidine hydrochloride during pregnancy; and 2) to provide intervention within the postnatal rearing environment to ameliorate early behavioral deviation. The project is a prospective longitudinal study from the neonatal period through year 2 1/2. There will be 60 PCP exposed infants recruited and 40 non-drug-exposed subjects being reared by biological parent(s) equivalent in socioeconomic status, family composition, maternal age and education to the biological parents of the PCP subjects. Since prenatal drug exposure is often confounded with a mixture of biological and foster home parenting, a complex research design is proposed. One group will be PCP exposed subjects who by court order are being reared in foster homes, half of whom will receive intervention and half who will not. A second group will be PCP exposed subjects who are discharged home to their biological parent(s), half of whom will receive intervention and half who will not. The third group will be non-drug exposed subjects being reared by biological parent(s) equivalent to the biological parents of the PCP subjects, half of whom will receive intervention and half who will not. There will be six data collection periods: neonatal, 4, 8, 13, 20, and 30 months. The infant variables to be assessed are selected to be salient developmental tasks for which drug-exposed infants may be specifically at risk: attention regulation, social interaction, motor patterns, and cognitive development,. Several comparisons will be made. PCP exposed infants will be compared to non-PCP exposed infants as to attention regulation, social interaction, motor patterns, and cognitive development through year 2 1/2. PCP exposed infants whose biological or foster parents receive intervention will be compared to those who do not. PCP exposed infants being reared in foster homes will be compared to those being reared by their biological parent(s).